--- a/grfspecial.c	Sun Nov 14 22:10:08 2004 +0000
+++ b/grfspecial.c	Sun Nov 14 22:25:21 2004 +0000
@@ -1821,6 +1821,7 @@
 	int i;
 
 	check_length(len, 1, "GRFInhibit");
+	buf++, len--;
 	num = grf_load_byte(&buf); len--;
 	check_length(len, 4 * num, "GRFInhibit");